I used to use interlnk and intersrv over null modem cable to network my xt to my 386 luggable then write the data to the zip drive that was attached to the parallel port of the luggable that way. Wasn't going to win any world records with the speed but it worked for everything I needed and pretty well. Plus I could network most of my systems that way and share files with any of them.
Well, it's native in Microsoft DOS 6.x and higher (can't recall how low it goes, I had it running fine in Dos 5.1 but i may have been using a boot disk). Looks like someone put up some very nice instructions on using interlnk here.